Security+ Exam Prep Question of the Week By James Michael Stewart November 2, 2012 Which of the following performs loop protection? 802.1x Spanning tree protocol VPN caching The answer is 2. Spanning tree protocol (STP) is a networking protocol that prevents looping transmission paths from being usable in a layer 2 network structure (i.e. comprised of bridges and switches). Related Courses Security+ Certification Boot Camp (SYO-301) Security+ Prep Course (SYO-301) CompTIA Advanced Security Practitioner (CASP) Prep Course In this article CertificationCompTIACybersecuritySecurity+Technology Join the Conversation Cancel Reply Will not be published. Website Notify me of follow-up comments by email. Notify me of new posts by email.